1. Field
The present disclosure relates to technologies of measuring a network state, and more particularly, to a terminal for accurately measuring a network state and a system and method of measuring a network state using the same.
2. Discussion of Related Art
A method which is most widely used among methods of measuring a network state may estimate queuing delay and a backlog queue. Here, the queuing delay refers to a time for which a data packet stands by in a queue of a router, and the backlog queue refers to the number of packets standing by in the queue of the router.
In an existing method of estimating the queuing delay and the backlog queue, a TCP-Vegas scheme has been mainly used. This is a method in which, by assuming that a minimum value (RTTmin) among Round Trip Times (RTTs) which are measured from the starting point of packet transmission is an RTT when queuing delay is zero, a value obtained by subtracting the minimum value (RTTmin) from a current RTT (RTTcur) is estimated as current queuing delay. Such a method may be suitable for being applied to a TCP protocol which is operated in an OS kernel, but when RTT is used as it is in an application hierarchical program in which a processing time such as processing switching or the like, other than a wireless network in which a deviation of the RTT is generated in accordance with a network state and queuing delay, or a time for which a packet stands by in a socket buffer is additionally reflected in the RTT, there is a problem that it is difficult to accurately measure the queuing delay. In addition, the backlog queue is calculated by the product of the queuing delay and a current reception rate of a reception terminal, and therefore there is a problem that an error of the queuing delay is transferred as it is to the backlog queue.
Therefore, there is a demand for a method that can accurately measure a network state by minimizing an error occurring when estimating the queuing delay and the backlog queue.